Active methylene phosphinic peptides: A new diversification approach

Simple, rapid, and efficient methods for P1′ diversification of phosphinic peptides have been developed, employing alkylation and Knoevenagel-type condensation reactions with active methylene phosphinic scaffolds, thus leading to a wide variety of diversified phosphinic and dehydrophosphinic peptides. © 2006 American Chemical Society

Chemoselective protection of solid-phase compatible Fmoc-phosphinic building blocks

(Chemical Equation Presented) An efficient four-step synthetic strategy able to fully discriminate hydroxyphosphinyl and carboxylic groups of Fmoc-phosphinic building blocks and related analogues has been developed. The proposed method applies selective acidic removal of the phenacyl (Pac) group from the hydroxyphosphinyl functionality and protection by the 1-adamantyl (Ad) group. Reductive removal of the Pac group from the carboxylic functionality leads to Fmoc-protected phosphinic pseudodipeptidic units suitable for phosphinic peptide and library development using solid-phase peptide synthesis (SPPS). © 2006 American Chemical Society

A versatile annulation protocol toward novel constrained phosphinic peptidomimetics

(Chemical Equation Presented) The development of a novel 3-center 2-component annulation reaction between α,ω-carbamoylaldehydes and suitably monoalkylated phosphinic acids is reported. Depending on the starting α,ω-carbamoylaldehyde, diverse phosphinic scaffolds varying in the size of their rigidity element, the nature and stereochemistry of substituents, and the participation of heteroatoms in the azacyclic ring system can be obtained in one synthetic step and in high yield. In addition, this methodology allows the synthesis of Fmoc-protected constrained aminophosphinic acids that can be easily converted to suitable pseudodipeptide building blocks compatible with the requirements of peptide synthesis on the solid phase. Finally, the careful choice of both substituents and protecting groups can provide functionally diverse, orthogonally protected constrained scaffolds for extended derivatization of the target phosphinic peptidomimetic structrures. © 2007 American Chemical Society

Antibacterial and anti-PAF activity of lipid extracts from sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata)

The anti-PAF and the antibacterial activities of lipid extracts obtained from cultured sea bass (Dicentrarchus labrax) and cultured gilthead sea bream (Sparus aurata) were evaluated. Total lipids of sea bass and gilthead sea bream exerted PAF-like activity while, in higher amounts they inhibited this PAF activity. Neutral lipids of both sea bass and gilthead sea bream contained only PAF antagonists while the polar lipid fractions contained both PAF antagonists and agonists. Total lipids of sea bass exhibited stronger PAF-like activity than did those of gilthead sea bream; however, neutral lipids of sea bass contained stronger PAF antagonists than did gilthead sea bream. Total lipids of both sea bass and gilthead sea bream exhibited antibacterial activity only towards Staphylococcus aureus (S. aureus) with those of sea bass being more potent. Subsequently, neutral lipids of both sea bass and gilthead sea bream also showed antibacterial activity against S. aureus and less so towards Escherichia coli (E. coli), while only neutral lipids of sea bass showed antibacterial activity against Enterococcus faecalis (E. faecalis). Sea bass neutral lipids were more active against S. aureus than were those of gilthead sea bream, while their activity towards E. coli was similar. Polar lipids of both sea bass and gilthead sea bream showed antibacterial activity against all bacteria strains. Sea bass polar lipids were more active towards S. aureus than were those of gilthead sea bream, while their activities against E. faecalis and E. coli were the same. The detected antibacterial activities of the lipid extracts isolated from sea bass and gilthead sea bream were observed in amounts equal to those that exerted either PAF inhibition or PAF-like activity, suggesting that PAF antagonists and agonists of fish lipids may be responsible for the antibacterial activity. © 2008 Elsevier Ltd. All rights reserved

In vitro anti-atherogenic properties of traditional Greek cheese lipid fractions

Given that platelet activating factor (PAF) is a crucial inflammatory phospholipid mediator that is implicated in the mechanism of atherogenesis, the presence of PAF inhibitors in food reinforces their nutritional value in terms of protection against cardiovascular diseases. The aim of the present study was to evaluate the anti-atherogenic (anti-inflammatory) properties of two different types of Greek cheese: Kefalotyri and Ladotyri. Total lipids (TL) of both types of cheese samples were extracted by the method of Bligh and Dyer and separated into total polar lipids (TPL) and total neutral lipids (TNL) by countercurrent distribution. TPL were further separated by preparative thin-layer chromatography (TLC). TL, TPL, TNL and the obtained polar lipid fractions after TLC separation were tested to determine their biological activity towards atherosclerosis based on the in vitro inhibition of PAF-induced platelet aggregation. Both types of cheese samples exhibited strong biological activity, and their lipids were potent PAF inhibitors. Comparing the two types of cheese samples, Ladotyri cheese polar lipid fractions were found to exhibit stronger inhibitory properties than those of Kefalotyri cheese. The fact that both types of cheese were found to contain PAF inhibitors highlights their nutritional value in terms of cardio-protection. © 2014 INRA and Springer-Verlag France

Exploiting the anti-inflammatory properties of olive (Olea europaea) in the sustainable production of functional food and neutraceuticals

Olive oil is an important lipid source of the Mediterranean diet which has been associated with lower incidence of cardiovascular diseases whereas olive pomace (OP), a natural by-product of olive oil production, has been found to contain micro constituents with antioxidant, antithrombotic and antiatherogenic activities. The evaluation of OP in order to produce sustainable functional food and neutraceuticals has been the subject of research over the last years. All recent data, focusing on the anti-inflammatory properties of olive oil derived from olive (Olea europaea) and OP along with the potential production of sustainable functional food and neutraceuticals, are presented in this review. © 2014 Springer Science+Business Media

Evaluation of sensory and in vitro anti-thrombotic properties of traditional Greek yogurts derived from different types of milk

Given that fermented dairy products exhibit high bioactivities against cardiovascular diseases (CVDs), the anti-thrombotic properties, fatty acid profiles and sensory properties of cow, goat and ewe derived Greek yogurts have been assessed and compared. The total lipids (TL), total polar lipids (TPL), total neutral lipids (TNL) were obtained and the polar lipid fractions were further separated by thin layer chromatography (TLC). These lipid samples (TL, TPL and TLC fractions) were subsequently assessed for their biological activity against atherosclerosis based on the in vitro inhibition of Platelet Activating Factor (PAF)-induced platelet aggregation. The fatty acid compositions of all yogurts were analyzed by Gas Chromatography with flame ionization detector (GC-FID). Goat yogurt lipids have been found to exert more potent inhibitory activity (i.e. lower IC50 values in both TL and TPL samples) in contrast to the corresponding fractions of cow and ewe yogurts. The observed sensory data indicates that ewe yogurt was the most palatable of all three Greek yogurts. © 201